A cobpoba



I Jan. 17,1928. 1,656,760

m A W. SCHRAMM CHAIR ELEVATING MECHANISM Filed Sept. 25, 1923 5Sheets-Sheet 1 Jan. 17, 1928. v A. w. SCHRAMM CHAIR ELEVATING MECHANISMFiled Sept. 25, 1923 5 Sheets-Sheet 3 Jan. 17, 1928. 1,656,760

4 A. w. scHRAMM CHAIR ELEVATING MECHANISM Filed Septf25, 1923 5Sheets-Sheet 4 Jail. 17, 192s.

A. w. SCHRAMM CHAIR ELEVATING MECHANISM Filed Sepi. 25, 1923 5Sheets-Sheet s @Qumd-m Patented Jan. 17, 1928.

UNl'l'ED S'YiA'l'ES ADOLZPH W. SCHIBAMMI, O1? RIVERTGEQ, NEW JERSEY,ASSIGNOI-t TO ELECTED DENTAL,

iv'mnnrncrunine cor/renn n 'rron OF PENNSYLVANIA...

O}? PHILADELPHIA, PEEHFSYLVANIA, A GOBEOBA- CHAIRELEV ATINGhIECI-IANISM.

Application filed September 25, 1923. Serial No. 664,697.

One object of this invention is to provide a novel elevating mechanismparticularly adapted for dental and barber's chairs,

whereby it shall be possible to conveniently control the raising andlowering of a chair body, and the invention especially contemplatesmeans for movingsaid body cont-in uously as opposed to intermittentlyacting means, in either direction for any desired distance withinpredetermined limits, together with means whereby the speed of movementis caused'to bethe same when the chair body is lowered as when it israised, or it desired: made different from the latter.

A further object of the invention is to provide novel means for limitingthe movement of the several parts of the device with a view topreventing damage from overtravel.

The invention also contemplates.elevating mechanism. including coaxialscrews together with novel means foroperatively connecting cert-ain'oisaid screws and novel means for prrmzntinp the actuating motor beingreversed until ithas come to rest.

The invention'fi'irther includ s automatic satety devices whereby thereversal of the motor is prevented until it and incidentally themechanism to which it is connected, has come to rest, together withmeans whereby the motor controlling switch is automatically releasedirom thecoutrol of the operator when the parts of the device has movedto *ithin predetermined distances of the limit oi? their safe travel ineither direction.

Another object of the invention is to provide novel braking means forcausing the downward speed of the chair body to be the same as itsupward speed, which mechanism shall also be available :tor holding thechair body with its applied load in any given position, as well as forpreventing itscoasting downwardly ;--the construction moreover beingsued asto operate silently.

I also desire to provide device of the gen,- eral character aboveindicated with novel meanstor mounting the motor so as to maintain thealignment of the motor shaft and the member driven therefrom, whichmeans shall be particularly adapted to permit of the motor. beingconveniently removed and replaced by another.

The invention also includes a novel form oi cover particularly designedto itacilitate the inspection of the mechanism and includnovel meanswhereby it may be conveniently and quickly moved into a positionpermitting 0r such inspection. 1

The invention likewise contemplates novel automatic means for supplyingand circulatlug lubricant for the elevating and guiding mechanism inorder that'lwear may be reduced to aminimumh t it further desire toprovide means for manually operating; the chair in event of failure oithe elevating motor to properly function or in the event of failure ofthe current supply. I

nese objects'and other advantageous ends I attainas hereinafter setforth, refierence being had to the which,

Fig. 1 is a plan of a chair constructed in accordance with my invention;

Figs. 2'and 3 are vertical sections taken respectively on the lines 2-2and 3-3 of Fig. lf a part of the enclosing casing being shown in Fig.Braised to permit inspection of the elevating mechanism;

l. is a vertical section on an enlarged scale, taken on the line l4,Fig. 1;

Fig. 5 is a transverse vertical section on the line 55, Fig. 4;

Fig. tl is a vertical section also on an eng larged scale, taken. on theline 6-6, Fig. 1;

Fig. 7 is a horizontal section on the line 7-7, Fig. 6; 5 i 1 Fig. 8 isan elevation of a portion of the motor reversing switch; A

Fic'j 9 is an elevation of the cam drum forming part of my invention;

Fig. .10 is an elevation of a detail of the invention, r i

Fig. 11 is an enlarged horizontal section taken through the telescopingscrews and the rollerswhereby they are splined together and,

Fig. 12 is an elevation partly in section illustrating the connectionbetween the switch and the cont-rolling lever. In the'ahove drawings, 1represents a base plate having a central circular opening in which isremovably mounteda pan-like supporting member 2 held inplace by suitablemeans such as screws (not shown). lhis pan is provided with an upwardlyprojecting flange 3 forming or'defining an annular reaccompanyingdrawings ,in

cess for the reception 01" the outwardly prohas a body portion 5 and anupwardly ex tending hollow column 6 constituting a container andguideway for certain elements hereafter referred to. i

'A portion of the body of the chair is indicated at 7 and this has aninverted dished form, being fixed to and carried by the up per end of avertically extending sleeve 8 to whose lower end is fixed an internallythreaded nut 9 slidably guided within asec- 0nd sleeve 10. The upperpart of this first sleeve 8 is also guided in a suitable bushirg' 11fixed within the up er end of said second sleeve 10. The upper part ofthe latter is likewise guided by a second bushing 12 mounted in theupper end of the column 6, while the lower end of said sleeve 10 hasfixed. to it a nut 13 which slidably engages and is guided by the innercylindrical sur face of the column Mounted coaxially within the sleeves8 and 10 is avertically extending screw 1 having fixed to its lower enda gear 15. The latter and the screw Ll are supported on a suitable ballbearing 16 carriedby the pan structure 2. This screw is engaged by thenut13 of the sleeve 10 so that said sleeve will move vertically up ordown when the gear and its attached screw are rotated. The nut 18supports a ball bearing 17 which in turn supports a tubular screw 18extending through the nut 9. These two telescoping screws 14 and 18 areoperatively connected so that they necessarily rotate together, whilebeing free to move longitudinally one over the other. For this purpose Imount on the upper end of the screw 14- two pairs of coaxial rollers 19(Fig. 11) and so form the interior of the screw 18 as to provideguideways for said rollers, which thus insure relative longitudinalmovement of said screws with a minimum friction. At the same time theabove construction insures that said screws are in effect keyed orsplined together so that they necessarily rotate together.

The nut 13 is rigidly fixed to the sleeve 10 which is prevented fromrotating in the column 6 by a longitudinally extending and preferablyintegral key 20, (Fig. 1) operative in a lteyway of the bushing 12 whichis fixed in the upper end of the column 6. Similarly the nut 9 is fixedto the lower end of the sleeve 8 which is provided wit-ha key 21 alsopreferably integral with the tube and longitudinally slidable through asuit able lreyway in the bushing 11 fixed in theupper end of the sleeve10.

Vi ith this construction and arrangement of parts, rotation of the gear15 causes rotation of the screws 14; and 18, and rotation of the screw14 will cause vertical movement thereon of the nut 13 and hence of thesleeve 10. This vertical movement of the nut 13 imparts a similarmovement to the hollow screw 18, which being rotated with the screw is,imparts relative vertical movement to the nut 9 and sleeve 8. The latteris consequently moved vertically at a speed,

. which, if the two screws have the same pitch,

structure considerable range of movement so the no chair bodyavill beraised to a relatively great height when the parts are at their upperlimit of motion.

It is especiall -x to be noted that the frame structure is ovided with adownwardly extending ige 22 coaxial with the screws 1ft and 18 aldesigned to extend immedia ely adjacent the body of the gear 15 so asto insure that this shall not separate from or move verticallyrelatively to the ball. bearing 13 or its supporting structure liilrevise the on er screw 18 has on its lower end an Otl'tvf extending flange18 whicn projects undc' a suitable annular shoulder formed on the lowerportion of the sleeve 10 so as to prevent the possibility of said screwmoving vertically relatively to the ball bearing 1? and the nut 13 onwhich it rests.

For driving the bevelled gear 15, 1 pro vide a second beve led gear 23frictionally connected to the hu Eli of a worm gear 25 2). The l gear isrotatably supported upon a fixed spindle 26 suitably mounted in a in nof the frame structure 5 and is dri era a worm 27 on a shaft actuatedmeansv hereafter described,

V To lock the spin in place it is iorined with a notched head (Fig. 10)designed to be engaged by the tooth o? a dog 26, having a slotconcentric with said spindle and designed for the reception of aclampingscrew 26.

For frictionally connecting the bevelled gear 23 with the n rm gear 25,I provide a ring 230 coaxial with said bevelled gear 23 'irictionallvdrawn against it by a series of screws 31 extending through the hub 24:of the worm. wheel 95 parallel to the spindle Each of these screws isyieldingly acted on by a bowed spring plate 32, (Fig. 4) mounted betweenits head and the adjacent face of the worm wheel 25. andthe-arrangeniont and proportions of the parts are such that slippagewill occur between the ring 30 and the bevelled gear 23 ween more than aundetermined load is applied to the latter:the device serving as asafety mechanism to protect the whole driving train from 28,1 form onthe motor casing a'pair of oppositely projecting lugs 34, and coaxiallywith the armature shaft 33 provide said motor with a sleeve projectingbeyond a plane portion of the motor casing which lies at right angles tosaid armature shaft. The face of that portion of the frame 5againstwhich the motor is to be mounted is likewise faced off, and.concentrically with the worm shaft 28' is recessed for the receptionofthe projecting end of the motor sleeve 35. with a pair of headed studs36, so positioned as to lie respectively under the lugs 34 when theendof the sleeve 35 is entered in the recess of said frame ;-the latterhaving an opening vertically above the Worm shaft 28 for the receptionof a bolt 37. This bolt is designed to be threaded into the upper andcentral portion of a clamping yoke 38, the lower ends of whose branchesrest upon the lugs 34, beyond which they are forked to respectivelyfitupon the studs 36 (Fig. 4).

ith this arrangement of parts, when it is desired to operatively connectthe motor with the worm shaft the sleeve35 is entered in the recess ofthe frame 5 so that the toothed end 33 of the armature shaft 33 mesheswith oroperatively connects to the correspondingly toothed end. 28 ofsaid worm shaft 28. The yoke 38 is then placed betweenthe body of themotor and the lugs 34 so that it extends over these and has the forkedends of its branches engaged with the studs '36, after which the" bolt37 is tightened, thus through the yoke so acting on the lugs 34 that theplane face of the motor is brought into and maintained in intimateengagement with the adjacent plane face of the supporting frame, whilethe two shafts 33 and 28 are operatively coupled in alignment.

For insuring that the downward movement of the chair shall'take place atthe same speed as .its upward movement and also for the purpose ofbringing the motor to rest when the electric currentis out off, Iprovide sultable mechanism such as that shown in Figs. 4 and 5, whichbroadly consistsof an automatic braking device applied in the presentinstance to the worm shaft 28, although obviously without departingfroinmy invention, itmay he applied at other-parts of the mechanismbetween the motor29 and the screw 14. This de vice includes in thepresent instance a re taining ring 39 threaded into the frame The frame5 is also provided structure 5 coaxially with the work shaft 28 andincidentally designed to adjustably retain in position the worm 27,carried by said shaft. This ring is preferably castellated. and isadjustablyheld in any given position by a toothed plate 40, (Fig. 5)having a slot 41 for the reception of a clamping screw 42- threaded intosaid frame. The outer face of the ring 39 is formed with holes for thereception of a suitable number of pins 43 projecting from and in. the

present instance, integral witha disc 44.

In said holes are suitable springs 45 tendipg to force outwardly saidpins and the c isc.

The outer portion of the worm shaft 28 is provided with a relativelycoarse thread 46 on which are mounted a relatively fixed nut 47 and anadjustable nut 48, respec tively provided with pairs of cooperativeprojections or teeth 49 and 50, whereby the rotation of the nut 48 islimited relatively to the nut 47. The latter is fixed in any givenposition on the screw 46 by a cotter pin 51, and between said nuts Imount a suitable coil spring 52 having its ends connectedto themrespectively so that it tends to turn the nut 48 on the, screw 46 in onedirection and opposes its movement in the opposite direction. Thissecond nut 48 is 4 provided with an outwardly extending flange andbetween the latter and the disc 44 is mounted a ring 53 of material,such as brake lining, for causing friction between these members.

lVith this arrangement of parts, when the armature of the motor 29 isturned in such a direction as to cause'elevation of the chair body, theshaft 28 and the worm 27 thereon turn in such a direction that the screw'46 tends tocause the nut 48 to back away from the disc and hencerelieve the friction between the flange of said nut.

and theifixed disc 44. As a result, this braking and regulating 'Cl8VlCGOlf6I'S-p1fl(3 tically no opposition or resistance to theabove notedrotation of the shaft 28 and the consequent elevation of the chairbody.If,

however, the direction of rotation of the motor is reversed or occurs intheopposite direction, as when the chair body is tobe lowered, the shaft28 and hence the screw 46, turn in such a direction that the nut 48 isautomatically movedtoward the disc 44, owing to thecombined action ofthe spring 52 and to the friction existing between the face ofits'flange, the friction ring 53' and the disc 44, as well asto-theinertia of the nut 48 or to the latter alone if said spring beomitted, as may be the case under certain conditions,

As a consequence of this rotation of the nut 48 and'the resultantincreased friction between itsflange and the fixed disc 44, the

further relative rotation of the two nuts can and the frictionalresistance to the rotation nut 48 is so far rotated on the screw46 thatits pins 50 come into engagement with the pins 49 of the fixed nut47.Thereafter he occur and the continued rotation of the shaft 28 and theoperation of the motor is opposed by the constant frictional force dueto vthe above device. If during this operation, the current should becut ioi'i from the motor, the trictionalresistance applied by saiddevice serves as abralce which brings to rest the motor armature and thetrain of mech anism connected thereto, so that coasting or downwarddrifting of the chair body is eti'ectually prevented. By means of theadjustable nut 47, the amount of the braking force applied may be soregulated that the motor andits associated, parts are caused to operateat any desired speed when the chair body is moving downward, and whencurrent is cut off from the motor will bring it to rest and thereafterhold it motionless. As soon as the downward movement of the chair bodyhas been arrested, the above described brakingor load-regulating deviceis again in condition to permit either the relatively tree'upwardmovement of the chair body without opposition, or to exert a frictionalopposition to its downward movement as above described.

For providing the necessary lubrication to the above described mechanismand also for supplying a working fluid for governing the motorcontrolling elements of the apparatus, l utilize a liquid such as asuitable lubricating oil and form the hub of the bevelled gear 15 with,ormount upon it, an eccentric 54 (Fig. 3) having an annular groove orchannel 55 communicating through a passage .58 with an axial passage 59in the screw 14. Mounted on the eccentric 54 is a strap 56 having aneccentric rod 57 formed with a plunger 60 operative in an oscillatorycylinder 61. s The latter is mounted tooperate on aihollow spindle 62fixed in the. frame structure 5 and provided at its upper portion with avalve seat for the reception of a check valve 63. The hollow passage ofthis spindle communicates with the chamber of the cylinder 61 which hasalso a passage opening into the lower portion of the pan 2' andcontrolled by a check valve 65. The plunger 60 and cocentric rod 57 arehollow or tubular and the former has asuitable seat for the reception ofa spring-controlled valve 64; the arrange ment being such that therotation of the gear 15 reciprocates the eccentric rod and plunger 60,causing liquid to be drawn from the pan 2 into the chamber of thecylinder 61 and discharged there-from through said plunger andconnecting rod into the screw 14. It is-also delivered through thespindle 62 past'the valve 63 into the chamber of a cylinder 66 formed toextend vertically in a portion of the structure 5.

The upper end of the second screw 18 is normally closed by a plug 67having passages 68 leading outwardly from its hollow interior. Into thisplug is threaded a downwardly extending tube 69 making a sliding surfaceof the screw 18 as well as through passages 68 so as to lubricate thethreads of the screw 14. It may also enter other suitably placedpassages 8 and 10 so as to provide the desired lubrication for the otherparts of the telescopic elements of the chair elevating mechanism abovedescribed and from all-of these said. lubricant drains back into thepanQ for repeated use. From the lowerpart of the cylinder 66 I provide apas=age 71, (Fig. 6) whose area of cross section may be regulated andrestricted to any desired extent by a screw 7 2 and whichleads to adischarge pipe 73 whose outlet is so positioned as to deliver lubricantover the worm 27 and to its associated bearings.

In order to prevent accidental overtravel oi the chair-operatingmechanism in either direction and to permit of the apparatus beingreversed after it has been brought to either extremity of its possiblemovement, as well as to prevent the possibility of reversalof the motorwhile its armature is still turning, I provide the mechanism shown inFigs. 2, 3, 6 and7, which is particularly distinguished by the fact thatit utilizes the lubricating liquid as its governing medium.

For this purpose, the cylinder 66, (Fig. 6) has mounted within it aplunger 74 whose upper end is made conical as indicated at 74", so as tobe capable of co-operating with the suitably formed portion of a switchlever 75. This latter is connected to what in the present instance is avertically extending spindle 76, bya horizontal pivot 77 which extendsthrough va slot in said spindle so as to be capable of axially turningit. This spindle governs or is operatively associated with motorcontrolling mechanism or apparatus such ascertain relatively movablecontacts 78, 78, 79, 79 79 and 79, (Fig. 8) which coact with suitablefixed contacts 81-82 and 83--84 for controlling the starting, stoppingand direction of rotation of the motor.

Suitable means are provided for resisting movement of the spindle 76with its contacts from and for insuring its return to, a neutral or offposition, and for this purpose I provide a device such as a disc 85fixed to the spindle. This disc has a pair of pins 86 projec'ting fromone of its :t'aces so as to co operate with the ends of the branches ofa yoke 87 This is mounted on an arm 88 slidable in a suitable portion 89of the fixed supporting structure, and acted on by a spring 90, wherebysaid yoke is at all times pressed toward the pins 86, thus tending toreturn the spindle 76 with its attached parts to a mid or neutralposition.

The fixed supporting structure 89 coaxially with the spindle 76, isprovided with a hub or extension 91 on which is rotatably mounted thecontrolling lever '92 for starting, stopping andcausing reversal of themotor, and this lever is connected by a link 120, (Fig. 1) with an arm121 fixed to a vertical 1y extending spindle 122 (Fig. 2) whichlikewisehas fixed to it a foot lever 123 projecting from the base. Said lever 92has an arm 93 formedwith an upwardly projecting rib 94 having anupwardly opening central recess 95 (Fig. 12) designed for the receptionof the switch lever 75 under certain conditions, it being noted thatsaid rib slopes upwardly on both sides to this centrally placed recess.As shown inFig. 6, the lever 92 has a pair of upwardly projecting posts130 designed to cooperate with the arms of a yoke 131 whose body 132 isslidably guided in an opening in the structure 89. A'spring 133 on thisbody at all times presses the ends-of the yoke toward the posts 130 andtends to return the lever 92 to or retain it in its neutral or midposition. The parts are so designed and arranged that when, owing to thepresence of liquid under pressure in the cylinder 66, (Fig. 6) theplunger 7 4c is forced to .its upper limit of motion, it is capable ofswinging the switch lever 7 5 on its pivot 7 7 to such aheight as tomove it out of the recess 95 and thus operativelyuncouple it from thefoot or main lever 92. Moreover,

owing to the conical form of the end 7 4 of this plunger 74:, which isso positioned as to be operative when the levers 92 and 75 are in theirneutral or 0E positions, the lever 75 will ride up on this end as saidtwo levers approach the neutral or oft position and will be disconnectedfrom said foot lever. If, however, said plunger is in its lowerposition, it obviously cannot operate on the lever 75 and hence cannotthen act to disconnect it from the control lever 92.

With this construction, if for example the foot controlled lever 92 bemoved from its neutral position in either direction, it carries with itthe switch lever 75to which it is nor mally coupled. As a consequence,current is supplied to the motor29, which thereupon vided by the plunger60 and cylinder 61.

This latter not only supplies lubricant to the various parts oftheapparatus but at once causes said lubricant to act upon the plunger 74,which is thereupon moved to its upper position.

It now the foot lever be released and allowed to return to its citposition, the switch lever 75 automatically disconnected from ituponreaching its neutral or off position, owing to the "fact that it ridesup on the conical plunger end 74 andis swung upwardly on its pivot 77out of the recess "95. Consequently even tliough the foot lever be againoperated from its off position, the motor cannot be started in eitherdirection until it comes torest, since it is first necessary that thepump plunger 60 cease to operate and for the liquid in the cylinder 66to leak out through the restricted passage 71. When this has occurred,the plunger 74: falls and again permits the switch lever 7 5 to enterthe recess 95 of the lever 92 so that this may be again moved by theoperator. From the above it will be obvious that it is not possible forthe operator to cause reversal of the motor until its armature has firstcome to rest.

Damage to the latter is thus eii'ectually pre vented, since it is animpossibility to supply said motor with current while its rotor is stillmoving under its momentum .or is being driven by the weight of the chairbody and its associated parts.

In order to prevent the motor being continued in operation with aresulting injury to the apparatus after the-chair body has been moved toits allowable limit of movement in either direction, I provide on thetube 10 two projecting pins or lugs 100, (Fig. 3) positioned to operatein cam grooves 101 and 102 formed in a cam drum 103' fixed to a verticalspindle 104 suitably supported on the trame,preferably on a portion ofthe column 6. On the lower end of this spindle is an arm 105 whichextends between the branches of a forked arm 106 (Figs. 1, 3 and 6)fixed to an oscillatory spindle 107, supported so as to extendhorizontally under the switch lever'75. Fixed on said spindle is asleeve having .two cam portions 108 and 109 shaped to cooperate with theswitchlever 75 when this is in the two positions in which the nrovablecontacts 78 and 79 engage the cooperating fixed contacts of theelectrical controller.

When the chair body is moved by the operation of the motor toward andinto its ex treme upper position for example, one of the projections 100on the sleeve 10 entersthe cam groove 102 ionexample, which is so shapedthat as *a result the cam drum 103.

and hence the spindle 104 is turned through a predetermined angle. Thearm 105 is thus likewise given an angular movementas is since the secondone of the projections 100' so cooperates with the cam grooves 101 toturn the spindle 101 'nto such a position that the part 108 of the camsleeve similarly raises the switch lever 75 out of the recess of theoperating lever, leaving it free to re turn to its oil position in whichthe apparatus is permitted to come to rest without possibility ofovertravel and consequent damage.

lit is to be noted that if after the switch lever has been automaticallydisconnected from the operating lever at the upper limit of travel ofthe chair body for example, said latter lever may be again connected tosaid switch lever by permitting the former to move to the neutralposition. The motor however, can only be started in such a direction asto cause downward movement of the chair body, since the cam 109 willagain disconnect the switch lever 7 5 from the operat-ing lever beforethe motor is connected to the supply circuit. If, however, the operatinglever be moved in such av direction as to. start the motor in thedirection necessary to lower the chair body, it will carry with it theswitch lever 75 and cause closing of the contacts onthe controllernecessary to cause operation of themotor as desired. I Y I For norma lyenclosing and protecting the above described mechanism, 1 mount on thebase plate 1 a relatively heavy casing ring 110 fastened to the base 1by'suitable bolts 111. ()n this ring rests thelower end of an enclosingcasing 112, whose upper end extends under the downwardly flanged portion7 of the chair body andhas a-central opening from, which depends asleeve 113. On the upper end of this latter is fastened a ring 117loosely resting on the uppe end of the casing 112 and designed to coactwith v a second sleeve 114 whose. upper end is fixed to an outwardlyextending flange of the tube 8 from which it depends; This second sleeve114: has at its lower end an outwardly projecting flange 1115 designedtoengage an inwardly projecting flange 116 at the upper end of the outersleeve 113, so that as the chair body is elevated, tlie two. flanges 115and 116 will come together, after which as the chair body continues torise, the sleeve 113 will be drawn out of the main part 112 of theenclosing casing. As a result the elevatmg mechanism is completelyenclosed, not only when the chair body is in its. lower position, butalso in any of its elevated provide a plurality of books 118 pivoted;

on the inside of the depending part of the chair body 7 and designed tocooperate with outwardly projecting pins or lugs 119 on the upper end ofthe casing 112. As the chair body is elevated by the operation of themotor, the hooks 118 are moved into engagement with these pins so thatsaid body carries with it the casing 112 and the sleeve 113. Access maythereupon be had to the motor and other parts of the associatedapparatus.

1 claim. 7 c

1. The combination in chair elevating mechanism of a chair body; amotor; and. means for transmitting power from said, motor to raise thechair body comprising a supporting 7 structure; a fixed spindle mountedin said supporting structure; a gear driven by the motor and rotatablymounted on said spindle; a second gear rotatably mounted on. the firstgear; and a slip clutch operatively connecting said gears under normalconditions.

2. The combination in chair elevating mechanism of. a supportingstructure; a shaftjournaled therein; a motor having its casing formed toengage a portion of said supporting structure; the adjacent ends. ofsaid shaft and the armature shaft of the motor being formed toseparablyengage each other; and means for detachably clamping the motorto the supporting structure to maintain said shafts in operativeconnection, the same consisting of lugs on the motor, with a yolremounted on the supporting structure and engaging said lugs to maintainthe motor and supporting structure in engagement. 3. The combination inchair elevating mechanism of a supporting structure; ,a shaft journalledtherein; a motor having its casing formed to engage a portion of saidsupporting structure; the adjacent ends of said shaft and the armatureshaft of the motor being formed to be detachably coupled; and means forclamping the motor to the supporting structure to maintain said shaftsinoperative connection, the same consisting of a pair of lugs on themotor; posts on, the supporting structure; a yoke fulcrumed on the postsand engaging the lugs; with a threaded member for holding the yoke inoperative position.

1. The combination with a chair body of mechanism for raising said body;an enclosfor connecting the body to said casing comprising a hook tocause said casingto be raised with the body to exposesaid mechanism.

5. The combination with a chair body of mechanism for raising said body;a casing comprising telescoping members enclosing said mechanism andconnected to the latter so as to be raised and lowered therewith; a mainenclosing casing; and means including a hook for connecting said maincasing to the body at will to cause it to be raised there with.

6. Apparatus comprising a pair of screws; a nut for one of said screws,the other of said screws engaging said nut; and means for preventing arelative longitudinal movement between said nut and said last-mentionedscrew.

7. In combination, a pair of shafts adapted to be detaohably coupled;supporting members for the respective shafts, one of said members havinga shoulder;and a fulcrumed element mounted on the other of said membersand adapted to engage said shoul der, whereby said members may besecured in engagement.

8. In combination, a pair of shafts adapted. to be detachably coupled;supporting members for the respective shafts, one of said members havinga shoulder; an element fulcrumed on the other of said members andpositioned to engage said shoulder; and means for exerting-a force onsaid element, whereby said members may be secured in position.

9. In combination, a pair of shafts adapted to be oetachably coupled;supporting members for the respective shafts, one of said members havinga shoulder; a post on the other member; an element fulcrumed on saidpost and engaging said shoulder; and

means for exerting a force on said element,

whereby said members may be secured in position.

10. In combination, a pair of shafts adapt ed to be detachably coupled;supporting members for the respective shafts, one of said members havinga pair of shoulders; a yoke fulcrumed on the other of said members withthe respective arms thereof in engagement with said shoulders; and meansfor exerting a force on said yoke, whereby said members may be securedin position.

11. In combination, a pair of shafts adapt ed to be detachably coupled;supporting members for the respective shafts, one of said members havinga pair of shoulders; a yoke fulcrumed on the other of said members withthe respective arms thereof in engage-- ment with said shoulders; andmeans extending from said first-mentioned member for exerting a force onsaid yoke, whereby said members may be secured in position.

12. In combination, a pair of shafts adapted to be detaohably coupled;supporting members for the respective shafts, one of said members havinga pair of posts; a pair of lugs on the other member; a yoke fulcrumed onsaid posts and engaging said lugs; and a member for holding said yoke insuch position as to secure said supporting members in position. i

13. Apparatus comprising a pair of hollow telescoping drive members; anda pipe positioned Within the inner member and supported at one end onthe outer member, the other end of said pipe being in sliding engagementwith the adjacent wall of the inner member.

14:. Apparatus comprising a pair of hollow telescoping drive members; apipe positioned within the inner member and'supported at one end on theouter member: and

means for supplying a lubricant to the other end of said pipe.

15. Apparatus comprising a pair of chollow screws rotatably coupled inrelative longitudinal movement; a pipe positioned with in the innerscrew and supported at one end.

- on the outer screw; and means for supplying a lubricant to the otherend of saidpipa- 7 l6. Chair elevating mechanism including a pair ofscrews; sleeves having portions re spectively engaging said screws, saidsleeves having perforations; and means for supplying lubricant throughsaid holes to the coacting surfaces of said sleeves.

anorrrr w. SGHRAMM.

